Abstract: In order to solve the shortcomings of straw briquettes, such as producing large amount of smoke during burning, failing to improve the calorific value due to its high volatile matter content, the briquettes were further carbonized for enhancing the calorific value and decreasing the amount of volatile component. The carbonization conditions, including carbonization temperature, heating rate and time, were investigated. Results showed that the calorific value of the produced carbon stick was increased obviously from 14.48 MJ/kg to 19.08 MJ/kg after heating at 300 ℃ for 1 h, with heating rate at 5 ℃/min. Density decreased from 1.31 g/cm³ to 0.99 g/cm³, and the fixed carbon increased obviously to approximately 40% after carbonization. Besides, smoking time and fume decreased dramatically due to the drastical decrease of violate matters from 60% to 40%, approximately, while the yield was 52.5%. This meets the demand of industry and daily life utilization.

Key words: wheat straw, briquettes, carbon stick, carbonization, combustion performance